Other Tuned Instruments
In addition to MPE Controllers, here are some tuned musical instruments, instruments optimized for playing 12-tone notes and chords, as opposed to instruments designed more for control of sounds. Over the years, I've found these to be particularly interesting. All of these have no mechanical sound generation but rather use a sensor-based interface and software synthesis.
Most of these instruments use a non-traditional note arrangement. Here is a very useful site that explains the various note layouts and their relative merits. Also, there is a very interesting iPad app called Musix Pro that allows you to try out playing a variety of hex and grid-based note arrangements.
The Hyperkeys keyboard from Jeff Tripp's Perfect Fretworks looks at first glance like a normal midi keyboard, but it's much more. Its keys move in-and-out as well as up-and-down, and it tracks both z-axis position and the force on a key when down on a fully polyphonic basis. This gives it excellent note expression, as demonstrated in these superb performances by Jordan Rudess: Glass Segovia and Seetar.
The Opal Keyboard from Shape of Music. These unique keyboards consist of an array of hexagonal keys arranged in an ingenious note layout called a Sonome, conceived in 1983 by an Englishman named Peter Davies, the founder of Shape of Music. This isomorphic layout is unique in that the notes increment in minor 3rds as you move up/left diagonally, in major 3rds as you move up/right diagonally, in 5ths as you move up vertically, and in semitones as you move to the right. Here's a video of Für Elise (at 1:30 minutes in) and other music performed on the Opal. And here's a funny cartoon video about the benefits of the sonome, created by the former C-Thru Music that formerly sold keyboards based on the sonome layout and has now ceased operations.
The Thummer from ThumTronics is a small hand-held instrument with an isomorphic note arrangement known as Wicki-Hayden. A big bonus is that the keys are independently velocity- or pressure-sensitive and 2 thumb joysticks control pitch bend and modulation, or any other parameters you assign them to in the external synthesizer. The product actually includes 2 independent keyboards, one for the left and right hands, easily permitting different sounds from each hand. Unfortunately, the Thummer never made it to market despite the laudable efforts of its creator, Jim Plamondon. Here's a video.
Starr Labs' Z-Board is a novel keyboard consisting of a large array of parallel rows of chromatic notes with the rows offset by musical fourth intervals. This layout is similar to fourths tuning on guitar, in which the guitar's 2 high strings are tuned a semitone higher, thereby insuring that a fourth interval exists between all strings and changing the guitar into an isomorphic instrument. By the way, just about everything Starr Labs makes is innovative, original and well-designed.
Starr Labs' Microzone is another very creative hex layout. In this case, the hex keys are laid out similar to black and white piano keys except that the keyboard is angled slightly so that the octaves are on the same horizontal plane. This layout is used in Starr Labs' U-648 and U-990 Microzone keyboards, and you can see a video explaining the layout here.
The Chromatone Keyboard uses a unique isomorphic key layout called Jankó after its inventor Paul von Jankó, who created it in 1882. It consists of a row of keys at whole-tone intervals (C, D, E, F#, G#, A#, C, etc.), with another whole-tone row above it containing the in-between notes (C#, D#, F, G, A, B, etc.) These 2 rows are then repeated twice as rows 3, 4, 5 and 6. Given that the rows are offset from lower rows by 1/2 a key width, this was a precursor to the emerging hex key layouts. Here's a video.
The Marimba Lumina by Buchla & Associates looks like a marimba but is much, more more. Each of the "bars" can sense the position and speed of movement of each of its 4 color-coded mallets. In addition to its use as a electronic marimba, it provides a very wide range of possibilities for sound control in performance. In addition to sending MIDI messages, it has a built-in synthesizer. Here's a video.
Leon Gruenbaum's Samchillian Tip Tip Tip Cheeepeeeee is a radical keyboard idea from that uses relative pitch instead of absolute pitch as in a conventional music keyboard. You specify one of a number of scales, then hitting the +1 or -1 keys will move to the next higher or lower note in the scale. For example, if you specify a major scale, then repeatedly pressing the +1 key will play C, D, E, F, G, etc., and repeatedly pressing the +2 key will play C, E, G, B, etc. It sounds difficult but listen to this fast solo recording that was performed in real time on the device. Here's a video performance by Leon.
The Akai EWI and EVI, created by Nyle Steiner, are electronic controllers based on the note layouts of wind and valve instruments, respectively. However, the exquisitely design wind sensor and motion-sensing keys of these instruments provide a very high degree of note expression. Here's a 2010 video of Nyle Steiner demonstrating his latest wind controller.
The Yamaha WX7 is a similar controller for players of wind instruments.